The document discusses Earth's global rainfall distribution and the different precipitation patterns in tropical, temperate, and polar regions. Tropical regions near the equator experience heavy rainfall due to hot, humid weather and converging winds. Temperate zones between the tropics experience light rainfall and four distinct seasons as air usually sinks at the surface. Polar regions have very cold temperatures year-round, which prevents air from holding much water vapor, resulting in low snowfall amounts of around 10 inches annually in some areas.